A Reasoned Defence
The classic text for Christian apologetics (the defence of the faith) is 1 Peter 3:15, “…but in your hearts honour Christ the Lord as holy, always being prepared to make a defence to anyone who asks you for a reason for the hope that is in you. This tells us why every Christian should be prepared to defend the faith: because God says so. Naturally, God has a reason why he would say so as well, and that reason is the salvation of sinners and the glory of his Name. Therefore, we are to be ready always.
The answer which we must be prepared to give is a well-reasoned one, as the original Greek apologia (from where we get the word “apologetics”) indicates. It would thus be unacceptable for Christians to defend their faith in a sloppy way, giving no heed to rules of reasoning.
Logic as a Tool
I want to share with you some common mistakes people make when arguing about the Christian faith. In doing this, let me be clear: our faith doesn’t rest upon logic or reason. Christian faith is reasonable, but it isn’t rationalistic. Faith is produced by the Holy Spirit through the Word, built upon the solid bedrock of the gospel promises found in God’s Word.
However, that doesn’t leave reasoning out of the picture. Pastors use it in their sermons all the time, and you can find examples of it throughout our confessions. Logic is a tool for communication and persuasion. Moreover, just as there are laws in mathematics and laws of physics, so also there are laws of logic. It’s part of the created order—absolute, not relative. Therefore, to defend the gospel effectively, it’s necessary to know a few basics about reasoning.
The most important basics to know are informal fallacies—errors in reasoning having to do with content rather than structure. Since these are common and easy to diagnose, let’s go over a few so you can watch out for them in your own reasoning and gently point them out in others.
1. Ad Hominem
This error in reasoning is by far the most common and the one unbelievers tend to exploit the most. The name comes from Latin and means “to the man.” With this fallacy, the argument shifts away from the issue at hand and instead attacks the other party’s character.
We see this error frequently when critics attack Christians by calling them hypocrites or pointing out historical failures. By arguing this way, they shift attention away from the core question: Is Christianity true?
But we must be careful not to fall into the same trap. Christians could just as easily respond by pointing to the atrocities of historic regimes led by atheists. There’s plenty of mud around if one knows where to look for it, but this type of argumentation doesn’t befit those who are to sanctify the Lord in their hearts.
2. Poisoning the Well
This is a variation of the ad hominem fallacy. The name comes from a historic debate where one side suggested his opponent didn’t give much weight to the truth because of his religious background.
An everyday example would be saying something like, “Why should I expect you to agree with what I’m saying? You’re an unbeliever.” A statement like that poisons the well; it makes discussion impossible. Christians should be charitable in their conversations. After all, you simply don’t know whether the Holy Spirit is currently working for the redemption of that person.
3. Hasty Generalization
With this fallacy, a single isolated case or a small number of cases is used as the basis for a sweeping conclusion. The argument assumes that what is true in one instance must be true in every case.
An unbeliever might use it like this: “I know a Christian who cheats on his taxes and yells at his wife. You just can’t trust Christians, so I wouldn’t want to be one.” Christians must also be careful about making hasty generalizations about unbelievers. One can make generalizations, but they must be grounded on facts and relevant to the actual argument.
4. False Cause
This argument claims that one event caused another event when no such relationship has actually been proven. A historical example is the ancient claim that the Roman Empire disintegrated because of Christianity —an argument to which Augustine responded at length in The City of God.
From our own perspective, we might commit this error if we say: “Morality declined right after the acceptance of evolutionary theory, therefore the theory of evolution is solely to blame for today’s societal issues.” While there may be a connection, a simple chronological sequence doesn’t equal proof; you must show how it is true with further evidence. In other words, correlation does not prove causation.
5. Equivocation
To equivocate means to change the meaning of a key word in the middle of an argument. For example, in debates surrounding capital punishment, people sometimes appeal to the commandment “You shall not kill.” They argue that because God says we cannot kill, capital punishment is always wrong.
The problem here rests with the word “kill.” Most modern translations accurately render that specific Hebrew word as “murder.” The commandment is a prohibition against the unlawful taking of life either intentionally or through negligence, not an absolute injunction against killing in general (such as lawful execution or self-defense). The lesson here is that we must use our terms in exactly the same sense throughout a discussion.
6. Appeal to Authority
If asked, “Why do you believe in the resurrection?” a Christian might answer, “Because the Bible tells me so.” Many unbelievers would call this a fallacious appeal to authority. However, not all appeals to authority are fallacious. As long as the authority is reliable and competent, the appeal is justified. In this case, the person pointing to the Bible must be ready to defend its authoritative and reliable character.
Conversely, unbelievers often appeal to a different kind of authority: consensus (the argument that because millions of people do not believe, it can’t be true). We recognize that truth doesn’t depend on a headcount. It’s better and more God-honouring to discuss the inherent character of the Christian faith than to get caught up in debates about how many people accept it.
Conclusion
God wants the best from his people, and that includes how they go about defending the faith. The holy priesthood of believers ought to have a good knowledge of Scripture, but they must also be able to present and defend the truths of Scripture in a coherent, reasonable, and orderly way. This eminently honours God, the source and foundation of all our reasoning.
